JP3597408B2 - Image data inspection device - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to an image data inspection apparatus for inspecting image data obtained by laying out images and characters constituting a printed matter, and in particular, comparing image data before correction and image data after correction with a difference. The present invention relates to an image data inspection device that detects the
[0002]
[Prior art]
In the process of producing a conventional printed matter, there is a proofreading operation for inspecting whether or not the plate making is completed as instructed and performing correction, and several proofreading operations have been performed until the final printed material is finished. In recent years, plate making is performed by a computer, and when digital image data is used to output the final plate making film, printing plate, or the like, the image data before correction and the image data after correction are compared and inspected, and correct calibration is performed. An image data inspection apparatus called a plate inspection apparatus for inspecting whether or not the image data has been inspected has been put to practical use.
[0003]
As such an image data inspection apparatus, for example, there is an apparatus described in JP-A-7-219202. In this apparatus, the image data before correction and the image data after correction are stored in a bitmap format developed by RIP (Raster-Image-Processing), respectively, and the difference is detected by comparing the pixels in the co-located table. Like that. In this apparatus, since image data is directly compared, there is an advantage that a consumable material such as a plate making film or a proof print is not required. Further, since the image data is stored in a bitmap format and compared, there is an advantage that a defect due to the RIP development itself can be inspected. Since the image data after the RIP development is binary image data, the comparison is easy and the inspection can be performed in pixel units.
[0004]
[Problems to be solved by the invention]
In the above equipment, the difference is extracted and inspected, but the final confirmation as to whether the difference is a correct correction by calibration work or a defect is still performed visually by the operator. That is the current situation. As a method of displaying the difference points, a method of blinking the difference points in a specific color on a color monitor, a method of printing with a printer, and the like are used.
[0005]
However, the image data tends to have a higher resolution, and it may be difficult for an operator to visually confirm a minute difference in pixel units. In particular, the resolution of a color monitor or the like used by the operator for confirmation is lower than that of the final printed matter. For this reason, when the image data in which the difference is detected is displayed at a low resolution according to the color monitor, the difference itself may not be displayed.
[0006]
The present invention has been made in order to solve the above-described problems, and provides an image data inspection device that can easily confirm a difference, particularly an image data inspection device that can be easily confirmed using a low-resolution display unit. With the goal.
[0007]
[Means for Solving the Problems]
The invention according to claim 1 is an image data inspection apparatus for inspecting image data obtained by laying out images and characters constituting a printed matter, wherein the image data is converted into bitmap image data. Means, comparison means for comparing two or more image data converted by the conversion means to detect a difference point, emphasis means for thickening the difference point detected by the comparison means, and said thickening processing Display means for converting the difference thus obtained from the resolution of the image data to the resolution of the display means for display.
[0008]
According to a second aspect of the present invention, in the first aspect, the degree of emphasis of the emphasizing means can be changed.
[0009]
The invention of claim 3 is the invention according to claim 2, the enhancement degree of the emphasis means based on the resolution of the resolution and the image data of the display means is set.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the connection between the image data inspection device according to the present invention and its related devices.
[0011]
In FIG. 1, an image data inspection device 1 is connected to an image data creation device 2 and an image output device 3. The image data creation device 2 is a device that edits various data such as an image input by a scanner and characters input from a word processor to create image data representing a printed matter, and is referred to as, for example, a DTP (Desk-Top-Publishing) device. Computer system. The image data creating device 2 handles various types of image data depending on the system. The image output device 3 is a device that outputs an image based on the image data created by the image data creation device 2, and is, for example, a recorder that records an image on a plate making film, a printing plate, or the like. The image output device 3 uses bitmap image data obtained by RIP-expanding the image data created by the image data creation device 2.
[0012]
On the other hand, the image data inspection device 1 according to the present invention includes a RIP developing unit 10, a data processing unit 11, and a display unit 12. The RIP developing means 10 performs RIP processing on the image data created by the image data creating device 2 and converts the image data into bitmap image data. The data processing means 11 is a computer system provided with appropriate operation means and storage means, and inspects the image data. Note that the data processing unit 11 corresponds to a comparing unit and an emphasizing unit in the present invention. The display unit 12 displays the result of the inspection performed by the data processing unit 11, and is a color monitor in the present embodiment.
[0013]
In the above embodiment, the RIP developing unit 10 is included in the image data inspection device 1, but may be included in the image data creation device 2 and the image output device 3. The RIP expanding means 10 may be configured as a single piece of hardware, or may be configured so that processing is performed on a computer by appropriate software. Further, the image data creating device 2 and the image data inspection device 1 may be shared by the same computer system.
[0014]
Next, the bitmap format image data according to the present embodiment will be described. FIG. 2 is a diagram showing a configuration of image data in a bitmap format. In FIG. 2, it is assumed that the image data in the bitmap format is composed of M and L pixel columns, each having an image width and height. Each pixel has a binary pixel value of “0” or “1” for each of the four colors Y (yellow), M (magenta), C (cyan), and K (black). Hereinafter, the respective pixel values of the Y, M, C, and K colors in the n-th pixel are defined as Yn, Mn, Cn, and Kn. (N = 1 to LM)
[0015]
Next, the operation of the image data inspection apparatus 1 according to the present embodiment will be described using the flowchart of FIG. First, in step S1, the image data created by the image data creating device 2 is converted into bitmap image data by the RIP developing unit 10. In the present image data inspection apparatus 1, since two image data are compared to detect a difference, two image data, that is, image data before correction and image data after correction are prepared. . The image data before correction may be converted into a bitmap format in advance and stored in a storage unit such as a hard disk.
[0016]
In step S2, a difference is detected by comparing the image data before correction converted to the bitmap format with the image data after correction. This comparison is performed by comparing pixels at the same coordinates for each pixel value of each color. As the comparison result of each pixel, the following four can be considered.
(State 1) When there is no difference between pixels.
(State 2) When there is an added pixel.
(State 3) When there is a deleted pixel.
(State 4) There is a pixel whose color has been corrected.
[0017]
State 1 is a case where the pixel values are the same for all four colors of YMCK. In this case, there is no difference between the image data before and after the correction. State 2 indicates a case where the pixel value before the correction is “0” and the pixel value after the correction is “1” in the pixel value of any color of YMCK. In this case, the pixel of the corresponding color is added after the correction. State 3 indicates a case where the pixel value before correction is “1” and the pixel value after correction is “0” in any of the pixel values of the YMCK color. In this case, the pixel of the corresponding color has been deleted after the correction. When the state 2 and the state 3 are mixed, the state is referred to as a state 4. In other words, it indicates that the color of the pixel is corrected as a result of the deletion of a pixel of a certain color and the addition of a pixel of another color.
[0018]
The following difference point data is generated according to the above-described states 1 to 4. For example, in the case of the state 1, the pixel of the same coordinate is set to [Yn, Mn, Cn, Kn] = [0, 0, 0, 0]. In the case of the state 2, the pixel of the same coordinate is set to [ Image data such that [Yn, Mn, Cn, Kn] = [0, 1, 0, 0] is generated as difference point data. Similarly, in the case of state 3, the pixel of the same coordinate is set to [Yn, Mn, Cn, Kn] = [0, 0, 1, 0], and in the case of state 4, the pixel of the same coordinate is set to [Yn, Mn, Cn, Kn] = [0, 0, 0, 1]. Thus, when a pixel is added, the pixel is displayed in M color, when the pixel is deleted, the pixel is displayed in C color, and when the pixel is corrected in color, the pixel is displayed in K color. Data is generated. Note that this difference data may be newly created, or any of the above image data may be converted.
[0019]
FIG. 4 is a diagram for explaining the difference data. In FIG. 4, the image data D1 before the correction lacks the character "" in comparison with the image data D2 after the correction, and conversely, the image data D2 after the correction is replaced with the image data D1 before the correction. In comparison, it is assumed that the "cloud" of the character "" is missing. If the difference point is detected in the example of the image data, the difference point data D3 is generated such that “Dark point” is displayed in C color and the character “S” is displayed in M color.
[0020]
In the difference data D3, if the difference is minute, it is difficult for the operator to visually confirm the difference. In particular, since the resolution of the display unit 12 is generally smaller than the resolution of the image data, if the resolution is converted according to the display unit 12, the difference may not be displayed. Therefore, in the next steps S3 and S4, the difference is emphasized so that the worker can see it.
[0021]
Here, the emphasis processing in the present embodiment is, for example, processing for increasing the difference. The fattening process is a process in which, as shown in FIG. 5A, if the target pixel P is “1”, the surrounding pixels Q within one pixel around the target pixel P are also converted to “1”. . In the thickening process, the thickening amount can be changed by changing the range of the peripheral pixel Q. The degree of emphasis in the present embodiment indicates the range of this peripheral pixel Q. For example, when the range of the peripheral pixel Q is one pixel around the pixel of interest P, the degree of emphasis is 1; And the same shall apply hereinafter.
[0022]
Hereinafter, details of the emphasis processing will be described. In step S3, the degree of emphasis in the emphasis processing is first determined. In the present embodiment, the degree of emphasis is determined based on the output size and resolution of image data in the image output device 3 and the display resolution of the display unit 12. Hereinafter, for ease of explanation, the display means 12 is assumed to be a color monitor having an effective display line number of 1200 × 1200 lines, and the output dimensions and resolution of the image data are set to 5 × 5 inches and 1200 dpi, respectively. In this case, the resolution when the image data is displayed on the color monitor is 1200/5 = 240 dpi. That is, image data having a resolution of 1200 dpi is displayed on a color monitor at 240 dpi. If the resolution conversion is generally performed by the simplest pixel thinning, the image data is thinned to 240/1200 = 1/5 and converted. Therefore, there is a possibility that a minute difference point of less than 5 pixels is not displayed. However, if one pixel on 1200 dpi is thickened by two surrounding pixels, that is, if one pixel is converted into 5 × 5 pixels, even if the pixels are thinned out to 1/5, the difference point pixels will not be lost. Therefore, in this case, if the degree of emphasis is set to at least 2 or more, it is possible to prevent the problem that the display unit 12 does not display the difference.
[0023]
In the above-described embodiment, the emphasis degree is set based on the resolution of the display unit 12 and the output size and resolution of the image data in the image output device 3, but the resolution of the display unit 12 or the resolution of the image data is set. The degree of emphasis may be automatically set based on at least one of the following. For example, the degree of emphasis may be determined in steps according to the resolution of the display unit 12 or the resolution of image data. Of course, the operator may manually select the degree of emphasis manually.
[0024]
In step S4, an emphasis process is performed based on the set emphasis level. For example, FIGS. 5B and 5C show an example of a case where the "dark point" of the difference point data D3 is emphasized. In FIG. 5, the "cloud point" itself is simply displayed for easy understanding. As shown in FIG. 5 (B), by performing fattening processing on the surrounding pixels Q in two pixels around the pixel of interest P constituting the above “cloudy point”, the “cloudy point” as shown in FIG. 5 (C) is obtained. ] Can be represented by the pixel R subjected to the emphasis processing.
In step S5, the emphasized difference point data is displayed on the display unit 12. Then, the operator can determine the quality of the calibration work by checking the difference displayed on the display unit 12.
[0025]
【The invention's effect】
According to the first aspect of the invention, since the extracted difference can be emphasized, the difference can be easily confirmed.
Further, according to the invention described in claim 2, since the degree of emphasis of the emphasis processing can be changed, display means of various resolutions can be supported by the operator's selection.
In the invention described in claim 3. Thus the enhancement degree based on the resolution of the resolution and the image data of the display unit is automatically set, use the display unit and image data having different resolutions Can be easily handled.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a connection between an image data inspection device and a peripheral device according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating bitmap image data according to the embodiment of the present invention.
FIG. 3 is a flowchart showing an operation procedure of the image data inspection apparatus according to the embodiment of the present invention.
FIG. 4 is a diagram showing an example of difference point data according to the embodiment of the present invention.
FIG. 5 is a diagram showing an example of an emphasis process according to the embodiment of the present invention.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 image data inspection device 2 image data creation device 3 image output device 10 RIP expansion unit 11 data processing unit 12 display unit D1, D2 image data D3 difference point data P pixel of interest Q peripheral pixel

Claims (3)

An image data inspection device for inspecting image data obtained by laying out images and characters constituting a printed matter,
Conversion means for converting the image data into bitmap image data,
Comparing means for comparing two or more image data converted by the converting means to detect a difference,
Emphasizing means for thickening and processing a difference point detected by the comparing means;
A display unit for converting the thickened difference point from the resolution of the image data to the resolution of a display unit for display. The image data inspection device according to claim 1, wherein the degree of emphasis of the emphasis means can be changed. Image data inspecting apparatus according to claim 2, characterized in that the emphasis degree of said enhancement means on the basis of the resolution of the resolution and the image data of the display means is set.

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